This paper discusses some applications of the smear camera, one of the primary tools used to measure the velocity of rapid reaction fronts in an explosive or detonation reaction. Solid cylindrical explosive charges are normally initiated at a small area on the end of the axis. Due to the nature of propagation of a reaction front, the optical records, normally obtained from the periphery of a charge, are distorted and do not give a true measure of the front's velocity. For accurate measurement, long charges are ordinarily used and only a small portion of the total smear record is used to obtain the true velocity. A transformation equation has been derived whereby the data from smear camera records of the peripheral detonation of a short (L/D of 2.5) tetryl charge can be interpreted to obtain a detonation velocity measurement. The results are in excellent agreement with the values measured along the axis as well as with those published in the literature.
A. Robert Clairmont,
"Analysis of Optical Determination of Detonation Velocity in Short Charges," Optical Engineering 5(1), 050118 (1 November 1966). https://doi.org/10.1117/12.7971368